Plants are essential for any ecosystem. They provide all the energy for the
ecosystem, because they can get energy directly from sunlight. They use a process
called photosynthesis to use energy from the sun to grow and reproduce. They
also must get nutrients from the soil. Those nutrients get into the soil when
decomposers break down waste and dead
materials. Plants require space to grow and reproduce. The size of your ecodome
will influence how much space your plants have.

All other organisms in the food chain get energy from plants, either by directly
eating them as herbivores do, or by eating
plant eaters, like carnivores do. Omnivores
can get energy either by eating plants directly or by eating herbivores. Likewise,
decomposers get energy either from plants
or from the animals that eat them. Since all the energy in your ecosystem comes
from plants, you'd better have a lot of them.

There are several different kinds of plants, and not all animals can eat all
kinds of plants.

Grasses
are only edible to herbivores.
That is because the plants contain kinds of fiber that many omnivores
cannot digest efficiently. Many herbivores have specially adapted stomachs that
allow them to digest these plants.

Fruit-Bearing Plants make fruit. Herbivores
and omnivores can both eat fruit or vegetables
from plants, however. Fruit and seeds and sometimes vegetables are part of the
plant's reproduction, and generally the presence of pollinators
will help these fruit-bearing plants survive better and make more fruit.

Finally, there are a kind of plants called grains
which make seeds that can be eaten by certain kinds of omnivores but not all.
Humans and chickens
can eat grain seeds. Herbivores can eat
the whole plant.